Got another outputcache question!

I've been using outputcache for an aspx page that dynamically generates
images. This page is called many times by another page requesting images by
unique identifiers (id, width, etc). I noticed that when I have
Location="any" or by default my browser DOES NOT cache the images. If I
specify, Location="client", then they appear in my browser's temporary files
directory.

I assumed that "any" meant "all" HTTP 1.1 cacheable clients and the
originating server would cache the images. Is this not true? How about
"ServerAndClient"... does that mean both WILL cache or either MAY cache? Is
there an order followed? If so, how does one client in a chain of clients
passing along a single request (browser -> proxy .... -> server) know if a
returned reponse was cached along the way??

I'd like all clients to cache (if willing and enabled) for speed
performance, obviously. Currently, the reponses still seem rather slow for a
caching solution.

Thanks!
-Omar